Magnetic blow-out brush-holder.



No. 669,433. I 4Patented Mar. 5', 190|.

A vc. EAsTwoon.

MAGNETIC V8L0W-0UT BRUSH HOLDER.

(Application filed Dec. 3, 1900.) (No Model.)

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UNITED STATES PATENT OEEICE.

ARTHUR C. EASTVVOOD, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC CONTROLLER AND SUPPLY COMPANY, OF SAME PLACE.

MAGNETIC BLOW-OUT BRUSH-HOLDER.

SPECIFICATION forming part of Letters Patent No. 669,438, dated March 5, 1901.`

Application filed December 3, 1900. Serial No. 38,482. (No model.)

To all whom, t may concern.-

Beit known that I, ARTHUR C. EAsTwooD, a citizen of the United States, residing in Cleveland, Ohio, have invented certainImprovements in Magnetic Blow- Out Brush- Holders, of which the following is a specification.

My invention relates. to certain improvements in arc-rupturing devices, particularly io as applied to brush-holders, for use in connection with various forms of electrical apparatus.

It has for its object the protection against destructive arcing of contact-brushes, contact-segments, and all similar parts of electrical apparatus Where the current is broken or where commutation takes place between parts differing in potential.

In the accompanying drawings, Figure 1 is zo a side view of one form of myimproved brushholder. Fig. 2 is a sectional plan View of the same on the line 2 2, Fig. 1. Fig. 3 is a sectional view on the line 33, Fig. 1. Fig. 4 is a side view of a double brush-holder equipped z 5 with my invention', the magnet being connected between the brushes. Fig. 5 is a plan View of the same.

I have discovered that in deflecting 'or rupturing an electric arc by means of a magnetic 3o field the best eifect is obtained when the magnetic lines have a uniform direction through the arc. It will then be deflected in a certain definite direction and instantly ruptured. In cases where the magnetic lines have not a uniform direction through the arc, as in devices of this kind at present known to the art, the arc attempts at every point to take a direction normal to that of the said magnetic lines. Hence, these lines being scattered, the 4o arc swells or scatters instead of being instantly ruptured. This disadvantageous and destructive action I overcome by the arrangement of parts hereinafter described.

In the drawings, A A are the sides of the 4 5 brush-holder, preferably of the shape shown and made of iron. The upper portion of these sides is joined both mechanically and magnetically by a bar A', in the present instance of soft iron, which is threaded at the 5o ends andv has nuts (L a, holding the sides A A to it. On this bar is Wound a number of turns of an electrical conductor B, insulated therefrom and connected to the terminal of' the brush. It will be understood that I may, it desired, connect the ends of the wire on this magnet to any source ot electric current, it. not necessarily being in the same circuit as the brush.

Pieces of insulating material b b are fitted to the inside'of the lower part of the side pieces 6o A A, and there are end insulating-pieces b' b', fitting between the sides, as shown, the Whole being held together by the screws c c and forming, with the pieces b b, a brush-holder box or inclosure. A top insulating-piece b2 65 extends over this inclosure and is held to the pieces b b by screws c c', on which are nuts c2 c2.

A screw or bolt d is electrically connected to a carbon or copper brush D, fitting thein- 7o closure formed by the pieces b and b', and it passes 4through an openingin the insulatingpiece b2, there being a spring d' on it between the brush and the said piece b2, Nuts d2 on the bolt d serve to connect an electrical con` 75 ductor to the brush.

When current passes through the coil of wire B, it will be seen that the bar A becomes the core of an elecfromagnet, of which the sides A of the brush-holder form the poles. 8o This sets up a powerful directed magnetic field throughthe tip of the brush, as indicated by the dotted lines shown, and as the brush passes over the contacts E of a rheostat, for example, the are formed between the brush and the said contacts is at once defiected by the magnetic field and snapped. The direction in which the arc is deflected is of course dependent on the polarity of the brush-holder sides A A and on the direction of the fiow of 9o current through the arc.

It will be noted that a magnetic field always passes through the tip of the brush, no matter what may be the position either of the brush or of the segments under it, the said field being thus always in a position to most effectually accomplish its, purpose.

In Figs. 4L and 5 is shown a double brushholder equipped with my invention, this form being used where the brushes make electrical ico connection between two separate sets of contacts, as in many forms of controllers, rheostats, duc. The brushes are electrically insulated from the brush-holder by a construction Similar to that described in connection with Figs. l, 2, and 3, the one magnet supplying the magnetic eld for both brushes. These latter are preferably connected through the coil B, the magnet in both cases being energized only when the current is passing through the brushes and contacts.

It is to be understood that I do not confine myself to the abovedescribed arrangement of parts, as the brushes may be made to work oncont-acts in a Vertical plane or on the surface of a cylinder. Further, I do not coniine myself to the exact construction of brushholder here shown, as various modifications ot` it can be readily conceived by any one skilled in the art.

I claim as my inventionl. rlhe combination in a brushfnolder, of a brush for making and breaking electrical contacts, an inelosure in the holder retaining and guiding` said brush, means for electrically insulating' the brush from said holder, and means for causing magnetic lines of force to pass in a uniform direction through the space in the vicinity of the contact end of the brush, substantially as described.

2. The combination of a conducting-brush for making and breaking electrical connections, a magnet and pole-pieces therefor, said pole-pieces forming two sides of an inclosure for retaining said brush, substantially as described.

3. The combination of a conducting-brush for making and breaking electrical connections, a magnet, pole-pieces for the same inclosing the brush, and insulating material inclosing the brush between itand the said polepieces, a piece at one end of said insulatinginclosure and a spring between the brush and the said piece, substantially as described.

et. In a brush-holder having a magnetic blow-out, the combination of an electromagnet, pole-pieces therefor, a box or inclosure ot insulating material between said pole-pieces, and a brush in said inclosure, substantially as described.

5. The combination of an electromagnet having extended, parallel pole-pieces, an inclosure of insulating material attached to and supported between said pole-pieces, insulating material over one end of said inclosure, a brush for making and breaking electrical circuits movable within the inclosure, said brush having a terminal connected to it and extending through the insulating-piece at the end of said inclosure, substantially as described.

G. The combination in a brush-bolder of a conducting brush capable of making and lneakingelectrical connections, pieces of magnetic material on each side of the brush, an inclosing box of non conducting material whereby the pieces are electrically insulated from the brush said pieces being magnetically connected by a core of magnetic material, an insulated conductor on said core, said conductor being included in the electrical circuit of which the brush forms a part, substantially as described.

7. The combination of an electromagnet having extended parallel pole-pieces, an inclosure of insulating material attached to and supported between said pole-pieces, insulating material over one end of said inclosure, a contact-brush movable within the inclosure, a terminal connected lo the brush and extending through the piece at the end of the said inclosure and a spring on said terminal between the brush and theinsulating-piece, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing` witnesses.

ARTHUR C. EASTIVOOD.

Vitnesses:

C. W. CoMsTocK, HERBERT P. GLIDDEN. 

